This Dennison_readme20210608.txt file was generated on 2021-05-21 by Markus Foote ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Lookup Tables and Code for "Impact of Scene-Specific Enhancement Spectra on Matched Filter Greenhouse Gas Retrievals from Imaging Spectroscopy" 2. Author Information Principal Investigator Contact Information Name: Philip E Dennison Institution: University of Utah, Department of Geography Address: 260 S Central Campus Dr, Rm 4625, Salt Lake City, UT 84112 Email: dennison@geog.utah.edu Associate or Co-investigator Contact Information Name: Markus D Foote Institution: University of Utah, Scientific Computing and Imaging Institute Address: 72 S Central Campus Drive, Room 3750, Salt Lake City, UT 84112 Email: foote@sci.utah.edu Alternate Contact Information Name: Sarang Joshi Institution: University of Utah, Scientific Computing and Imaging Institute Address: 72 S Central Campus Drive, Room 3750, Salt Lake City, UT 84112 Email: sjoshi@sci.utah.edu 3. Date of data collection (single date, range, approximate date) 202005 to 202102 4. Geographic location of data collection (where was data collected?): University of Utah 5. Information about funding sources that supported the collection of the data: NASA Carbon Monitoring System Grant 80NSSC20K0244. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC BY NC 2. Links to publications that cite or use the data: Markus D. Foote, Philip E. Dennison, Patrick R. Sullivan, Kelly B. O’Neill, Andrew K. Thorpe, David R. Thompson, Daniel H. Cusworth, Riley Duren, Sarang C. Joshi, "Impact of Scene-Specific Enhancement Spectra on Matched Filter GreenhouseGas Retrievals from Imaging Spectroscopy," Remote Sensing of Environment. 3. Links to other publicly accessible locations of the data: None 4. Links/relationships to ancillary data sets: https://avirisng.jpl.nasa.gov/benchmark_methane_carbon_dioxide.html This related dataset includes the instrument radiance data files that are processed/reported by our article for methane and carbon dioxide. 5. Was data derived from another source? No 6. Recommended citation for the data: Markus D. Foote, Philip E. Dennison, Patrick R. Sullivan, Kelly B. O’Neill, Andrew K. Thorpe, David R. Thompson, Daniel H. Cusworth, Riley Duren, Sarang C. Joshi, "Impact of Scene-Specific Enhancement Spectra on Matched Filter GreenhouseGas Retrievals from Imaging Spectroscopy," The Hive: University of Utah Research Data Repository. https://doi.org/10.7278/S50D-0D0H-09A6 --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: Dennison_readme20210608.txt (this file) Short description: Describes this dataset. B. Filename: target_generation.py Short description: Python 3 script that reads the lookup tables and processes them to produce a scene-specific interpolated unit enhancement spectra. C. Filename: dataset_ch4_full.hdf5 Short description: Lookup table for methane simulations. HDF5 format. D. Filename: dataset_co2_full.hdf5 Short description: Lookup table for carbon dioxide simulations. HDF5 format. 2. Relationship between files: target_generation.py script loads data from either HDF5 lookup table to produce a scene-specific interpolated unit enhancement spectra 3. Additional related data collected that was not included in the current data package: https://avirisng.jpl.nasa.gov/benchmark_methane_carbon_dioxide.html This related dataset includes the instrument radiance data files that are processed/reported by our article for methane and carbon dioxide. 4. Are there multiple versions of the dataset? yes/no No -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Radiative transfer simulations using MODTRAN6 were performed at regular intervals on the five-dimensional grid of atmospheric and geometric parameters. We selected the discretization level for parameters within the generated lookup table to capture the trends and bounds expected for each parameter. Specifically, solar zenith angle was sampled at 5-degree increments between 0 degrees and 80 degrees. Ground altitude was sampled at 0 km, 0.5 km, 1 km, 2 km, and 3 km. Sensor altitude was sampled at 1 km, 2 km, 4 km, 10 km, 20 km, and 120 km. The top of the highest atmospheric layer modeled in MODTRAN is 120 km, and this equivalent sensor altitude setting should accommodate future satellite observations. Column water vapor was sampled at 1 cm increments between 0 cm and 6 cm. Separate lookup tables were generated for CH4 and CO2. Background concentrations of CH4 and CO2 were set to 1.85 ppm and 410.0 ppm, respectively, and used to scale the entire column of each greenhouse gas. CH4 and CO2 enhancements were added to a uniform layer from 0 to 500 m above the ground. For example, a CH4 enhancement of 1000 ppm·m would be simulated as a 2 ppm increase above background, with the concentration within the 500 m layer equaling 3.85 ppm. A mid-latitude summer atmosphere was assumed for all radiative transfer simulations that form the lookup tables, and DISORT multiple scattering was used. Simulations were run at a spectral resolution of 0.1 cm-1 to allow for convolution to hypothetical instruments with finer spectral resolutions than AVIRIS-NG. A range of simulated concentration enhancements was required for each parameter set. CH4 concentration enhancement above background level was simulated at 0 ppm·m and values doubling from 1000 ppm·m to 64,000 ppm·m (i.e., 0, 1000, 2000, 4000, 8000, etc.). CO2 concentration enhancement above background was simulated at 0 ppm·m and values doubling from 20,000 ppm·m to 1,280,000 ppm·m. Surface reflectance was set at 100%, which removes dependence of the modeled radiance spectrum on surface reflectance such that extinction occurs only through atmospheric absorption and scattering. The resulting sampling grid for the lookup table included 28,560 sample spectra for each gas. 2. Methods for processing the data: Simulation results were re-formatted from text files into the binary HDF5 files. 3. Instrument- or software-specific information needed to interpret the data: None. 4. Standards and calibration information, if appropriate: None. 5. Environmental/experimental conditions: Simulations described by our article. 6. Describe any quality-assurance procedures performed on the data: None. 7. People involved with sample collection, processing, analysis and/or submission: Philip E Dennison Markus D Foote Sarang C Joshi with input on the approach and final publication from: Patrick R Sullivan Kelly B O'Neill Andrew K Thorpe David R Thompson Daniel H Cusworth Riley Duren ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: dataset_ch4_full.hdf5 and dataset_co2_full.hdf5 ----------------------------------------- 1. Number of variables: 5 parameters ( enhancement concentration, solar zenith angle, sensor altitude, ground elevation, and column water vapor ), and 1 value ( absorption ) 2. Number of cases: 28560 simulations (each with a full spectrum of wavelength) (for each file/dataset) 3. Variable List A. Name: Wavelength Description: Wavelength values (in nanometers) of the wavelength axis B. Name: Absorption Description: Organized as a 5-dimensional array with dimensions: Wavelength enhancement concentration solar zenith angle sensor altitude ground elevation column water vapor Gas Enhancement Concentration values (parts per million): CH4: 0, 1000, 2000, 4000, 8000, 16000, 32000, 64000 CO2: 0, 20000, 40000, 80000, 160000, 320000, 640000, 1280000 Solar Zenith Angle values (degrees): 0,5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80 Sensor Altitude values (kilometers): [1, 2, 4, 10, 20, 120] Ground Elevation values (kilometers): [0, 0.5, 1.0, 2.0, 3.0] Water Vapor values (centimeters of condensed water): [0,1,2,3,4,5,6] 4. Missing data codes: None 5. Specialized formats of other abbreviations used None